But there is a lot of music out there that is not new, but undiscovered to many people, and what is apparent from NPR's coverage is that the major streaming services care less about this older music than promoting new music.

Not on streaming?

It turns out there is a lot of older music that is not available via streaming; it was only ever distributed on physical formats. It costs a non-negligible amount money to put and keep music online (not just the format transfer, but keeping track of rights and revenue), and if the music doesn't fit a service's criteria, it doesn't get posted. Jazz and classical music are only 1% each of the music market, but they and other genres produce a lot of music. Because there is so much music online, many assume that everything is online—but this is patently false.

Where does music go to die?

Modern streaming services, like the old-school record labels, don't take care of things that they don't think are going to make them money. This was part of the reason that the master recordings that burned in the Universal fire were stored in bad conditions and not cataloged well—Universal did not justify spending money on something that wasn't making money for them now. For streaming services, how do they decide when a song or album isn't worth posting on their platform? What about taking down songs or albums or genres that aren't earning enough money or have rights problems too complicated to deal with?

The Universal fire also showcases the ephemeral nature of recorded music—it has to be stored somewhere, even if it only is distributed via streaming. And unlike with physical media, where multiple copies are distributed that can be re-discovered, the access-only model streaming services control what who has a copy. What happens when streaming services decide an album that was only released on streaming should be taken down? And then a fire or simply bad cataloging causes the label or streaming service to lose track of the music? Or, maybe more likely, a popular streaming service suddenly goes bankrupt and shuts down overnight? (After all, Spotify has still never really made a profit).

In these cases, the music ceases to exist, for all intents and purposes. I predict that in 30 years, 2050, our era will be known in music circles as the “lost years” because there will be a lot of music that just isn’t available because no one was able to collect it and streaming companies decided it was not worth preserving.

Under protection...from preservation

Before the 2018 Music Modernization Act (MMA), there as no federal copyright protection for sound recordings produced before 1972, but instead a loose patchwork of state copyright applied. The MMA patched up this loophole, at least as far is streaming is concerned, but in doing so, it greatly extended protections for older music—which while these protections are good for a few artists and acts that are still well-known and popular, the protections are certainly bad for lesser-known music. Long copyright terms before passing into the public domain only hurt the chances that preservation will occur for these older recordings—and there are some major preservation problems. Magnetic media (such as cassette tapes) and even CDs not stored in optimal conditions may deteriorate in less than half of the time of their copyright terms, so we may get to the point where we are allowed to copy recorded music, only to find it doesn't exist anymore. The MMA does allow some preservation exceptions for recordings that aren't being commercially exploited, but there are some somewhat cumbersome steps you need to take first—and these exceptions would not have been part of the law at all if some library organizations hadn't lobbied for them. Finally, those services that do take the steps to preserve these recordings have to pay a lot of money to digitize and keep the recordings accessible—and who knows when someone will decide it is not worth it for their organization, either?